This allows arbitrary git configs to be passed in. For example:
`git config --global http.postBuffer 1048576000`
`git config --global http.sslCAInfo /path/to/cert/file`
`git config --global http.sslVerify false`
This flag takes a comma-separated list of `key:val` pairs. The key part
is passed to `git config` and must be a valid gitconfig section header
and variable name. The val part can be either a quoted or unquoted
value. For all values the following escape sequences are supported:
* `\n` => [newline]
* `\t` => [tab]
* `\"` => `"`
* `\,` => `,`
* `\\` => `\`
Within unquoted values, commas MUST be escaped. Within quoted values,
commas MAY be escaped, but are not required to be. Any other escape
sequence is an error.
Example:
`--git-config=foo.one:val1,foo.two:"quoted val",foo.three:12345`
This commit exposed a bug in runCommand() which modified its args when
they had an embedded space.
Faster builds and versions from tags. Also use alpine as a base image. We
need alpine for other architectures...
Also change the --wait flag to take a float for sub-second waits.